A sociologist is studying where homeless children in a particular city spend most of their time.  The sociologist queried homeless children in one homeless shelter downtown to carry out the survey. The population of interest is . The sample is .

A random sample of undergraduate students were asked if they worked for pay while taking classes, 52.7% of the students said ‘yes.’  Which of the following statistical inference procedures should be used to determine if the majority of the population works for pay while taking classes?

A large study of the efficacy of calcium and vitamin D supplementation in preventing fractures in health postmenopausal women enrolled 35,000 female subjects.  Here is a breakdown of the subjects’ ethnicities. Ethnicity Non-Hispanic White African-American Hispanic Asian Native American TOTAL Observed counts 29,440 3,239 1,471 705 145 35,000 % in U.S. population 75.6% 10.8% 9.1% 3.8% 0.7% 100% Which hypothesis test should be performed to determine whether this study successfully matched the ethnic diversity of the American population?

A sociologist is studying where homeless children in a particular city spend most of their time.  The sociologist queried homeless children in one homeless shelter downtown to carry out the survey. The population of interest is . The sample is .

Tree diameters are related to “growth rings” in trees and larger diameters are associated with taller trees. The scatter plot of a survey of 958 trees in an old-growth forest in Canada showed evidence of a linear relation between tree height (m) and diameter (cm).   The resulting least squares regression line equation  Height = 2.79 + 0.55× Diameter has an R2 value of 0.92. Which of the following is the slope of the least squares regression line equation?

Alcohol was a factor in about 10% of all automobile crashes in Ohio during 2016, but driver inebriation was present in almost 28% of crashes in which a fatality occurred. Here is some data on fatal vehicle accidents by season:        ALCOHOL INVOLVED NO ALCOHOL TOTAL WINTER 60 158 218 SPRING 73 172 245 SUMMER 110 243 353 FALL 70 247 317 TOTAL 313 820 1133 a.  What is the probability that a fatal vehicle accident in Ohio will occur in the winter?  Report your answer to 3 decimal places. b. What is the probability that a fatal vehicle accident in Ohio both occurs in winter and alcohol is involved? Report your answer to 3 decimal places. c.  Given the fatal vehicle accident happened in the winter, what is the conditional probability that alcohol is involved? Report to 3 decimal places. d.  What is the relative risk of an alcohol-involved fatal vehicle accident in Ohio in summer compared to winter? Report to 3 decimal places.   

A researcher conducted a study to investigate college safety.  He found that the more students a college has, the higher the crime rate in the surrounding area. The researcher claims that the correlation of 0.91 shows there is a strong causal relationship between the number of students and crime rates.  Explain what is wrong with this interpretation.

Which of the following graphs is appropriate to display one categorical variable?

Researchers took 100 people who had tested positive for COVID-19, 20 of whom had diabetes, and divided them into two groups: those with low levels of Vitamin D and those with normal levels of Vitamin D.  They looked at their medical records and found that those who had low levels of Vitamin D had a higher likelihood of severe COVID-19 symptoms. This is an example of

A researcher conducted a study to investigate college safety.  He found that the more students a college has, the higher the crime rate in the surrounding area. The researcher claims that the correlation of 0.91 shows there is a strong causal relationship between the number of students and crime rates.  Explain what is wrong with this interpretation.